Architected C70/Graphene Oxide Composites Prepared under Continuous Flow in a Vortex Fluidic Device: Implications for Supercapacitors

Abstract

Graphene oxide (GO) and fullerene C70 form architected-like C70/GO structures in high yield under continuous flow processing in a vortex fluidic device (VFD). The composite material forms within high-shear regimes in the thin film microfluidic platform, in the absence of surfactants, and indeed in the absence of any auxiliary substances. The structures form on intense micromixing of an o-xylene solution of C70 and a colloidal suspension of GO in dimethylformamide (DMF) at ambient conditions, with the liquids delivered through jet feeds at the same flow rate to the hemispherical base of the rapidly rotating quartz tube in the VFD, which is tilted at 45°. The particle sizes range from 0.5 to 3 μm, with their structure and properties explored using scanning electron microscopy, transmission electron microscopy, thermogravimetric analysis, X-ray powder diffraction, and Raman spectroscopy. The mechanism of formation of the architected-like structures is consistent with the general model of fluid flow in the VFD and arises from localized high-shear temperature regimes driving desolvation as the nucleation and growth step for crystallizing the fullerene component, which are then capped with GO.